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This study investigated the possibility of mineral (biotite, bentonite, fuller's earth)amendment to Fe(0)-based treatment system in the groundwater for enhancing nitratereduction. It was expected that amendment of mineral surfaces enhances nitratereduction by providing surfaces to form green rusts or reaction precipitates to preventpassivation of Fe(0) surfaces, as well as to adsorb produced ammonium. Batch tests for kinetics experiments were conducted by adding 20 mL solutions to 25 mLplastic vials containing 0.5 g of Fe(0) and 0.5 g of minerals. Other experiments werecarried out by changing the amount of bentonite, fuller's earth, and biotite (0.01-0.5 g) invials containing 0.5 g of Fe(0) with GW solutions. The reduction experiments wereperformed at room temperature (250.2C) for 64 h. The adsorption experiments wereperformed with bentonite and fuller's earth by batch method for 24 h. All the sampleswere shaken by a shaking incubator (shaking water bath, BS-31) with 150 rpm, filteredthrough 0.45 m PVDF filter (Whatman) and diluted for NOsub3/subsup-/sup, NHsub4/subsup+/sup analysis.Nitrate, sulfate, and chloride concentrations were measured by ion chromatography (DionexCX-120). Ammonium was measured using Nessler method with UV/VISspectrophotometer (DR4000/HACH). The solution pH in batch experiments wasmeasured using a pH meter (Horiba, Ltd. Kyoto, Japan). The concentrations of cations in groundwater were measured by inductively coupled plasma-optical emissionspectrometer (ICP-OES, Ultima 2C, Horiba). Includes 34 references, tables, figures.

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Edition: Vol. - No. Published: 11/01/2009 Number of Pages: 10File Size: 1 file , 1.1 MB